If a technical system is subject to vibrations during its use, its components are generally connected together in such a manner that the connection is elastic, and if necessary, contributes to damping the vibrations introduced into the system. An elastic connection of components is common, particularly in vehicle construction. In this case, relevant elastic connections between components are used for, among others applications, the suspension or fastening of the vehicle unit, and in the domain of chassis suspension. In the latter case, the elastic connection of the parts serves to increase the durability of the connections despite strong loads caused by vibrations that occur during the use of the vehicle, and to damp the vibrations, and thereby serves to decouple vibrations and acoustics of the vehicle and of the body. Due to the highly varied vibration frequencies and amplitudes depending on the road conditions and the vehicle speed, vehicle manufacturers endeavor to design the vehicle suspension such that, from the viewpoint of maximum comfort for vehicle passengers with respect to the damping behavior, the suspension extensively adapts to the different arising conditions.
The vibrations are damped by elastomer bearings disposed at various locations of the vehicle. For an optimal vehicle adaptation in terms of comfort, bearings that are switchable with respect to their rigidity are already known. For this purpose, adjusting cylinders are actuated by means of hydraulic units and are moved into or out of the bearing to vary the spring rate of a respective bearing. However, corresponding solutions are generally quite complex so that, with regard to costs, they are only conditionally suitable to some extent for use in series production.
From U.S. Pat. No. 4,973,077 an arrangement is known for connecting the torsion bar of a vehicle axle to a stabilizer device abutting at the torsion bar, in which the elasticity, or rather, the rigidity of the connection is variable by means of a hydraulic piston/cylinder unit disposed in its area. The cylinder of the corresponding piston/cylinder unit is disposed above the connection point from which projects the piston rod of a piston guided in the cylinder. Two chambers for a hydraulic damping means, separated from each other by the piston, are disposed in the cylinder. These chambers are connected to each other by a line system in which a switchable valve is inserted. The line passages between the chambers can be open or closed by means of the switchable valve, and therefore, the rigidity of the connection points can be switched between a state of minimum rigidity and a state of maximum rigidity. In order to avoid a system overload and a hard impact while in the state of maximum rigidity, that is, with the valve closed, a spiral spring and a pressure relief valve are disposed in each of the chambers. By means of the respective pressure relief valve, a bypass connection between the chambers can be enabled even when the main valve is closed. The construction of the described arrangement is, however, also relatively complex. This increases not only the costs, but possibly also the susceptibility to failure of a vehicle equipped with a corresponding solution. The arrangement serves to connect components directly resting on each other by fastening the components together.